demand and physical loads correlated to LBP in kindergarten personnel. Key words: Low back pain, Psychosocial factors, School personnel. Introduction.
Original Article
Industrial Health 2002, 40, 266–271
Psychosocial Factors Related to Low Back Pain among School Personnel in Nagoya, Japan Hirohito TSUBOI*, Kiyomi TAKEUCHI, Misuzu WATANABE, Reiko HORI, and Fumio KOBAYASHI Department of Health and Psychosocial Medicine, Aichi Medical University School of Medicine, Nagakute-cho, Aichi 480-1195, Japan Received October 11, 2001 and accepted March 20, 2002
Abstract: Related factors of low back pain (LBP) among school personnel were investigated. We designed a cross-sectional study employing questionnaires, which included a Japanese version of the Job Content Questionnaire. Subjects consisted of 3306 male and 3184 female school personnel in all public schools and kindergartens operated by Nagoya City, Japan. Prevalence of LBP in each work category was compared to that in general teachers of each gender after adjusting for age. Male teachers at schools for the handicapped and in classrooms for the handicapped showed significantly higher LBP prevalence. Among female participants, teachers at schools for the handicapped, physical education teachers, kindergarten personnel and school nurses displayed higher LBP prevalence. In work categories which demonstrated high LBP prevalence, low social support and low job satisfaction were related to LBP of school nurses despite low physical loads. High job demand and physical loads correlated to LBP in kindergarten personnel. Key words: Low back pain, Psychosocial factors, School personnel
Introduction Low back pain (LBP) has been shown to be an important health and socio-economic problem of occupational diseases, which plague a large segment of the population in industrialized countries1, 2). It signifies not only poor quality of life of individuals, but also decreasing labor productivity due to off-work, absenteeism and early retirement. Additionally, escalating medical costs are associated with LBP. Risk factors for LBP have been identified1, 3), including (i) individual factors such as body weight and age, (ii) biomechanical factors such as heavy physical load, lifting, twisted posture and vibration, and (iii) psychosocial factors such as job control, job satisfaction, etc. Interest has been increasing with respect to psychosocial factors relating to LBP during the past several years in occupational health research. Considerable evidence exists which indicates that *To whom correspondence should be addressed.
social and psychosocial factors play a major role in the symptom complex of LBP1, 3–9). In Japan, although the incidence of illness from employment is declining, frequency of LBP maintains high rates10). 70.0% of diseases resulting from employment in 1998 were caused by injuries during the working hours, 81.6% of which consisted of LBP10). Over the past decade, the rate of LBP in the manufacturing and construction industries has declined. In contrast, LBP rates in such industries as health and hygiene, service and entertainment, cleaning, butchery, etc., remain high10). This fact indicates the need to examine LBP risks in other professions, in addition to the manufacturing and construction industries, which have demonstrated high LBP risks. Thus, LBP care of school personnel should be investigated. Several studies have been published regarding LBP among schoolteachers11–13). However, data were compiled in limited small areas; moreover, few surveys in large fields such as entire compliments of personnel in large cities or prefectures have been conducted. In addition, very few reports regarding
PSYCHOSOCIAL FACTORS RELATED TO LOW BACK PAIN psychosocial factors on LBP among school personnel occur in the literature. A combination of high physical and psychosocial loads results in substantial increase in risk4); consequently, investigations into work-related physical risk factors for LBP should not lack quantification of the physical load. Moreover, these evaluations should account for confounding by individuals as well as psychosocial factors. In the present study, the objective was to determine whether physical and psychosocial occupational factors are associated with work with respect to LBP in school personnel. Consequently, we investigated the contribution of physical and psychosocial factors of LBP based on school type, work category and gender.
Subjects and Methods Study group Subjects consisted of male and female school personnel working at 31 kindergartens, 262 elementary schools, 109 junior and 15 senior high schools, and four schools for the handicapped operated by Nagoya City, Japan. This survey was conducted at the time of the teachers’ annual mandatory health check-up in 1997. Self-administered questionnaires, which included items pertaining to LBP and related factors, were delivered to the participants prior to the health screening. Questionnaires were collected on the day of the health checkup. The entire process was conducted with regard to the attendees’ privacy protection. Informed written consent was obtained in all cases. Data collection This survey covered basic demographic variables such as age, gender, years of experience, school type, position, specialty in education and present physical status. The questionnaire consisted of 167 items in 24 categories such as work classification, teaching subject, medical history, indicators concerning jobs, i.e., job demand, job control, job satisfaction, etc., by modified Japanese version of Job Content Questionnaire (JCQ)14, 15). In order to investigate occupational physical factors, three items of physical load in the JCQ and two items of sustain were employed. Questions pertaining to LBP were classified into four grades. (1) “I have pain in my back almost every day (5–7 days per week)”, (2) “I have pain in my back on several days per week (3–4 days per week)”, (3) “I have pain in my back on a few days per week (1–2 days per week)”, (4) “I seldom or never have pain in my back (less than one day per week)”. The two former grades were defined as possessing subjective LBP.
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Statistical analyses Data were analyzed by SAS software (Ver. 8.1) for Windows OS. Cochran-Mantel-Haenszel chi-square (CMH) test was used for examination of distinct LBP prevalence among personnel classifications. The unpaired t-test was utilized for comparison of various factors of LBP. A p value less than 0.05 was considered significant. Adjustment by age was calculated using the number of subjects exhibiting LBP and the expected number.
Results Questionnaires were delivered to 10351 school personnel (men 5122, women 5129). Responses were collected from 6490 subjects (3306 men, 3184 women). The response rate was 62.7% (men 63.3%, women 62.1%). Prevalence of subjective LBP was 20.4% and 23.2% among men and women, respectively. After adjusting for age, the prevalence among women was significantly higher than that among men (CMH test, p
